5. Long-answer questions (70 words)
a. Write any five differences between water (a compound) and salt solution (a mixture).
Answers
Answer:
Salty water has ionic salts dissolved in water, whereas distilled water has had virtually all ionic salts removed and is ideally considered pure water.
Explanation:
Composition
The substances which are found in the mixtures are not in fixed quantity, that means their ratio varies. But in the case of compounds, the elements are present in fixed quantity, that means their ratio is fixed.
Properties
The properties of the mixtures also vary (not fixed) as it depends on the type of substances and the quantity by which these are being mixed. For the particular type of compound, the properties are fixed and do not vary, as the elements present in the compounds are fixed and are in the fixed ratio.
Formula Mixtures do not have a certain formula.
Compounds have a specific formula, depending on the constituents present.
Separation
The substances of the mixtures are easy to separate by different physical methods like filtration, chromatography, evaporation.
The elements are not easy to separate and if done than it is by chemical methods.
Substances No new substances are formed from the mixtures, due to the unchangeable properties of its constituents.
There is always formation of the new substances, due to the mixing of the chemical properties of the different constituents.
Melting/Boiling point
Mixtures do not have fixed melting or boiling point.
The compound once formed, have fixed melting and boiling point.
Heat change
There is no heat change, or involvement of energy is observed when mixtures are made. There is a heat change, and energy is used or released during the formation of the compounds, as it is a chemical reaction.
Examples
Alloys like brass, bismuth, chromium, oceanic water (salt and water), mixtures of gases, etc. Compounds like Baking soda, Methane, Salt, etc.